1. Field of the Invention
This invention relates to a picture image monitoring system for monitoring a change of a picture image of a monitoring object area, and more particularly to a picture image monitoring system which can effect a monitoring operation from a remote location by way of a communication channel.
2. Description of the Prior Art
An exemplary one of conventional picture image monitoring systems of the type mentioned above is a monitoring camera system for the prevention of crimes. One of such conventional monitoring camera systems is shown in FIG. 14. Referring to FIG. 14, the monitoring camera system shown includes a video camera positioned to photograph a monitoring object area, and a TV (television) monitor and a video tape recorder (VTR) both connected to the video camera. A picture image of the monitoring object area is photographed by the video camera and recorded by the VTR while it is displayed on the TV monitor. A watching operation of the TV monitor and a judging operation for occurrence of an abnormal condition are performed by a watchman.
In this manner, with a conventional monitoring camera system for the prevention of crimes or a like monitoring system, a watching operation of a screen and a judging operation for occurrence of an abnormal condition all rely upon manual operation. Consequently, there is a problem that the accuracy in monitoring depends to a great extent upon fatigue or increase in stress of a watchman or upon a difference in capacity between individual watchman. Further, where manual operation is relied upon, the detecting accuracy is high for such a great change of a picture image that occurs over an entire screen, but it is a problem that a change of a picture image which occurs at a limited portion of a screen is likely overlooked. It is another problem that, as the number of monitoring object areas increases, the monitoring accuracy is deteriorated to a great extent.